Autor: |
Farfán Espuny, María José
Aparicio, Luis López Calderón, Isabel |
Departamento: | Universidad de Sevilla. Departamento de Genética |
Fecha: | 1999 |
Publicado en: | Applied and Environmental Microbiology, 65 (1), 110-116 |
Tipo de documento: | Artículo |
Resumen: |
The
HOM3
gene of
Saccharomyces cerevisiae
codes for aspartate kinase, which plays a crucial role in the
regulation of the metabolic flux that leads to threonine biosynthesis. With the aim of obtaining yeast strains
able to overproduce threonine in a controlled way, we have placed the
HOM3-R2
mutant allele, which causes
expression of a feedback-insensitive enzyme, under the control of four distinctive regulatable yeast promoters,
namely, P
GAL1
,P
CHA1
,P
CYC1-HSE2
, and P
GPH1
. The amino acid contents of strains bearing the different con-
structs were analyzed both under repression and induction conditions. Although some differences in overall
threonine production were found, a maximum of around 400 nmol/mg (dry weight) was observed. Other factors,
such as excretion to the medium and activity of the catabolic threonine/serine deaminase, also affect threonine
accumulation. Thus, improvement of threonine productivity by yeast cells would probably requi... [Ver más] |
URI: http://hdl.handle.net/11441/40234
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